Conclusions:Although power was limited and larger studies are needed, we failed to find evidence for greater benefit of increased SSRI dose versus continuation of current dose for panic disorder symptomatic after 6 weeks at moderate dose. Further, augmentation with CBT or medication optimization with clonazepam augmentation in nonremitted panic after 12 weeks of an SSRI did not differ, suggesting that both are reasonable next-step options. However, low overall remission rates in this comorbid refractory population suggest that better predictors of response to specific treatments over time and additional interventions are needed.